Staff and Scientist Biographies

Kirk Johnson, PhD

Vice President of Research & Collections and Chief
Curator, Denver Museum of Nature & ScienceDr.
Johnson joined the Museum in 1991 after earning his doctorate
in geology and paleobotany from Yale University. He studies fossil
plants, terrestrial stratigraphy, geochronology, and dinosaur
extinction and has published many popular and scientific books and
articles. He is best known for his research on fossil plants, which
is widely accepted as some of the most convincing support for the
theory that an asteroid impact caused the extinction of the
dinosaurs. His research has taken him to Alaska's Bering Sea, the
Brazilian Amazon, the Canadian High Arctic, the rainforests of New
Zealand, the Gobi desert, India, China, Patagonia, and the American
West. His book, "Cruisin' the Fossil Freeway," won the Colorado
Humanities award for best nonfiction book in 2007.

Ian Miller, PhD

Chair, Department of Earth Sciences, Curator of
Paleontology, Denver Museum of Nature & ScienceDr. Miller
received his PhD in geology and geophysics from Yale University in
2007. Dr. Miller studies fossil plants, paleoclimate, paleoecology,
and tectonics. Dr. Miller's current research projects include the
uplift history of the Colorado Front Range; the displacement of
geologic terranes on the west coast of North America;
Cretaceous-Tertiary plant diversity in the Denver Basin; the
taxonomy of Late Jurassic through Eocene floras in the American
West; and the fossil plants of the Grand Staircase Escalante
National Monument.

Steve Holen, PhD

Curator of Archaeology, Denver Museum of Nature &
ScienceDr. Holen
joined the Museum in 2001 after completing his doctorate in
anthropology at the University of Kansas. Dr. Holen has more than
30 years of experience in Great Plains archaeology and extensive
experience with public education in a museum setting.

His research has focused on the Clovis people-the earliest
well-known North American human culture at 13,000 years old. He has
studied Clovis use and long-distance movement of stone tools in the
central Great Plains of North America. He has also excavated
several pre-Clovis mammoth sites that date between 16,000 and
20,000 years old. These sites are significant because they reveal
evidence that humans were in North America long before the Clovis
people. This is one of the most hotly debated topics in North
American archaeology.

George Sparks

President & CEO, Denver Museum of Nature &
ScienceGeorge Sparks,
President & CEO since November 2004, received a master's
degree in aeronautics and astronautics from MIT, and a bachelor's
degree in aeronautical engineering from the United States Air Force
Academy. Sparks served as an Air Force pilot and was an assistant
professor of aeronautics at the United States Air Force Academy.
From 1979 to 1999, he worked for Hewlett-Packard. From 1999 to
2003, he was a vice president for Agilent Technologies. Sparks has
worked closely with Denver Public Schools and has served as a board
member for many Colorado organizations, including the University of
Colorado President's Leadership Class, Colorado MESA, Colorado
Forum, the Public Education and Business Coalition, Colorado Bright
Beginnings, and the Colorado Advisory Council of the Trust for
Public Lands. He also serves on Mayor John Hickenlooper's Early
Childhood Education Leadership Team.

Daniel Fisher, PhD

Professor of Ecology and Evolutionary Biology and Claude
W. Hibbard Collegiate Professor of Paleontology, University of
Michigan
Dr. Fisher completed his PhD in Geological Sciences at Harvard
University in 1975. In 1979, he moved to the University of
Michigan. Shortly after arriving in Ann Arbor, Fisher was called to
several local sites where remains of mastodons had turned up during
excavation of farm ponds. He is widely recognized as one of the
world's leading mastodon experts. He has recently expanded his
research to include woolly mammoths in northern Siberia. Dr. Fisher
is the guest curator for a large, traveling exhibit called
"Mammoths and Mastodons: Titans of the Ice Age," which opened March
5, 2010 at The Field Museum in Chicago.

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About the Denver Museum of Nature & Science The Denver
Museum of Nature & Science is the Rocky Mountain Region's
leading resource for informal science education. A variety of
engaging exhibits, discussions and activities help Museum visitors
celebrate and understand the natural wonders of Colorado, Earth and
the universe. The Museum is located at 2001 Colorado Blvd., Denver,
CO, 80205. To learn more about the Museum, check
www.dmns.org, or call 303-370-6000.

Many of the Museum's educational programs and exhibits are
made possible in part by generous funding from the citizens of
the seven-county metro area through the Scientific & Cultural
Facilities District.